Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1998-9-23
pubmed:abstractText
PTH-related protein (PTHrP) is a paracrine/autocrine factor produced in most cell types in the body. Its functions include the regulation of cell cycle, of differentiation, of apoptosis, and of developmental events. One of the cells which produces PTHrP is the pancreatic beta cell. We have previously described a transgenic mouse model of targeted overexpression of PTHrP in the beta cell, the RIP-PTHrP mouse. These studies showed that PTHrP overexpression markedly increased islet mass and insulin secretion and resulted in hypoglycemia. Those studies were limited to RIP-PTHrP mice of 8-12 weeks of age. In the current report, we demonstrate that PTHrP overexpression induces a progressive increase in islet mass over the life of the RIP-PTHrP mouse, and that, in contrast to some other models of targeted PTHrP overexpression, the phenotype is not developmental, but occurs postnatally. The marked increase in islet mass is not associated with a measurable increase in beta cell replication rates. A further slowing in the normally low islet apoptosis rate could not be demonstrated in the RIP-PTHrP islet. Thus, the marked increase in islet mass in the RIP-PTHrP mouse is unexplained in mechanistic terms. Finally, RIP-PTHrP mice are resistant to the diabetogenic effects of streptozotocin. The mechanisms responsible for the increase in islet mass in the RIP-PTHrP mouse likely lie in either very subtle changes in islet turnover or in early steps in islet differentiation and development. The ability of PTHrP to increase islet mass and function, as well as its ability to attenuate the diabetogenic effects of streptozotocin, indicate that further study of PTHrP on islet development and function are important and may lead to therapeutic strategies in diabetes mellitus.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
139
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3743-51
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:9724026-Animals, pubmed-meshheading:9724026-Animals, Newborn, pubmed-meshheading:9724026-Calcium, pubmed-meshheading:9724026-Disease Progression, pubmed-meshheading:9724026-Female, pubmed-meshheading:9724026-Gene Expression, pubmed-meshheading:9724026-Gene Targeting, pubmed-meshheading:9724026-Hyperinsulinism, pubmed-meshheading:9724026-Hyperplasia, pubmed-meshheading:9724026-Hypoglycemia, pubmed-meshheading:9724026-Islets of Langerhans, pubmed-meshheading:9724026-Labor, Obstetric, pubmed-meshheading:9724026-Mice, pubmed-meshheading:9724026-Mice, Transgenic, pubmed-meshheading:9724026-Parathyroid Hormone-Related Protein, pubmed-meshheading:9724026-Pregnancy, pubmed-meshheading:9724026-Proteins, pubmed-meshheading:9724026-RNA, Messenger, pubmed-meshheading:9724026-Streptozocin
pubmed:year
1998
pubmed:articleTitle
Progressive pancreatic islet hyperplasia in the islet-targeted, parathyroid hormone-related protein-overexpressing mouse.
pubmed:affiliation
Yale University School of Medicine, New Haven, Connecticut 06520, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't